Download MendeleyGreen/red light-sensing mechanism in the chromatic acclimation photosensor.
Nagae, T., Fujita, Y., Tsuchida, T., Kamo, T., Seto, R., Hamada, M., Aoyama, H., Sato-Tomita, A., Fujisawa, T., Eki, T., Miyanoiri, Y., Ito, Y., Soeta, T., Ukaji, Y., Unno, M., Mishima, M., Hirose, Y.(2024) Sci Adv 10: eadn8386-eadn8386
- PubMed: 38865454
- DOI: https://doi.org/10.1126/sciadv.adn8386
- Primary Citation of Related Structures:
8K9O - PubMed Abstract:
Certain cyanobacteria alter their photosynthetic light absorption between green and red, a phenomenon called complementary chromatic acclimation. The acclimation is regulated by a cyanobacteriochrome-class photosensor that reversibly photoconverts between green-absorbing (Pg) and red-absorbing (Pr) states. Here, we elucidated the structural basis of the green/red photocycle. In the Pg state, the bilin chromophore adopted the extended C15- Z , anti structure within a hydrophobic pocket. Upon photoconversion to the Pr state, the bilin is isomerized to the cyclic C15- E , syn structure, forming a water channel in the pocket. The solvation/desolvation of the bilin causes changes in the protonation state and the stability of π-conjugation at the B ring, leading to a large absorption shift. These results advance our understanding of the enormous spectral diversity of the phytochrome superfamily.
Organizational Affiliation:
Department of Molecular Biophysics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
